Onopordum acanthium (Cotton or Scotch Thistle) is a common
weed, especially in the Midlands. It is a large spiny plant that is
woolly hairy. The flower heads are large (usually several cm wide) and
have purple florets. Its relative,
O. acaulon, is similar but
does not produce an erect stem.
Cirsium vulgare is also
sometimes known as Scotch thistle. |